diff --git a/frontend/scripts/full-product-ui-smoke.mjs b/frontend/scripts/full-product-ui-smoke.mjs
index 008d61267..581629a3a 100644
--- a/frontend/scripts/full-product-ui-smoke.mjs
+++ b/frontend/scripts/full-product-ui-smoke.mjs
@@ -1135,7 +1135,7 @@ async function runCriticalInteractionSmoke(page, routeSpec, viewportSpec) {
   if (routeSpec.name === "search") {
     await page.getByText("20B readiness result", { exact: true }).first().waitFor({ state: "visible", timeout: 10_000 });
     await page.getByRole("tab", { name: "관계 원본", exact: true }).click();
-    await page.getByText("원본 메시지 필터로 관계 API를 조회합니다.", { exact: true }).waitFor({ state: "visible", timeout: 10_000 });
+    await page.getByText("선택한 원본 메일을 기준으로 관계를 확인합니다.", { exact: true }).waitFor({ state: "visible", timeout: 10_000 });
     await page.getByRole("tab", { name: "판단 보조", exact: true }).click();
     await page.getByText("외부 실행은 사용자가 메일, 일정, 관계 캡처 액션을 명시적으로 선택할 때만 진행됩니다.", { exact: false }).waitFor({ state: "visible", timeout: 10_000 });
     await page.getByRole("button", { name: "관계 캡처", exact: true }).click();
diff --git a/frontend/src/app/search/page.test.tsx b/frontend/src/app/search/page.test.tsx
index 8374b0953..048053000 100644
--- a/frontend/src/app/search/page.test.tsx
+++ b/frontend/src/app/search/page.test.tsx
@@ -121,7 +121,7 @@ describe("SearchPage", () => {
               parent_sender_email: "user@naruon.ai",
               source_message_id: "<q2@example.com>",
               source_thread_id: "thread-q2",
-              relationship_type: "colleague",
+              relationship_type: "Colleague",
               confidence_score: 0.85,
               next_action: "track_reply_and_tasks",
               action_reason:
@@ -158,16 +158,18 @@ describe("SearchPage", () => {
     await flushAsyncWork();
 
     expect(container.textContent).toContain("Q2 출시 계획 및 우선순위 조정");
-    expect(container.textContent).toContain("thread-q2");
+    expect(container.textContent).toContain("메일 흐름 연결됨");
+    expect(container.textContent).not.toContain("thread-q2");
     expect(container.textContent).toContain("답장 3건");
     expect(container.textContent).toContain("신뢰도 87%");
     expect(container.textContent).toContain("증거 바인딩");
     expect(container.textContent).toContain("맥락 정보");
     expect(container.textContent).toContain("메일 열기");
     expect(container.textContent).toContain("관계 맥락과 타임라인");
-    expect(container.textContent).toContain("발신자 DAG");
-    expect(container.textContent).toContain("track_reply_and_tasks");
-    expect(container.textContent).toContain("source=<q2@example.com>");
+    expect(container.textContent).toContain("발신자 관계");
+    expect(container.textContent).toContain("답장과 후속 작업을 확인합니다.");
+    expect(container.textContent).not.toContain("track_reply_and_tasks");
+    expect(container.textContent).not.toContain("<q2@example.com>");
     expect(container.querySelector("#search-detail-tab-context")?.getAttribute("aria-controls")).toBe("search-detail-panel-context");
     expect(container.querySelector("#search-detail-panel-context")?.getAttribute("role")).toBe("tabpanel");
 
@@ -315,7 +317,7 @@ describe("SearchPage", () => {
             parent_sender_email: null,
             source_message_id: "<capture@example.com>",
             source_thread_id: "thread-capture",
-            relationship_type: "colleague",
+            relationship_type: "Colleague",
             confidence_score: 0.85,
             next_action: "track_reply_and_tasks",
             action_reason:
@@ -376,10 +378,11 @@ describe("SearchPage", () => {
       expect(captureHeaders[headerName]).toBeUndefined();
     }
     expect(container.textContent).toContain("minjae@naruon.ai");
-    expect(container.textContent).toContain("track_reply_and_tasks");
-    expect(container.textContent).toContain(
-      "source=<capture@example.com> / thread=thread-capture",
-    );
+    expect(container.textContent).toContain("답장과 후속 작업을 확인합니다.");
+    expect(container.textContent).toContain("업무 관계");
+    expect(container.textContent).not.toContain("track_reply_and_tasks");
+    expect(container.textContent).not.toContain("<capture@example.com>");
+    expect(container.textContent).not.toContain("thread-capture");
   });
 
   it("renders a fail-closed error state when the search API rejects the query", async () => {
diff --git a/frontend/src/components/SearchLayout.test.tsx b/frontend/src/components/SearchLayout.test.tsx
index f9a47b66c..11cc81a19 100644
--- a/frontend/src/components/SearchLayout.test.tsx
+++ b/frontend/src/components/SearchLayout.test.tsx
@@ -30,7 +30,11 @@ vi.mock("lucide-react", () => ({
   X: () => <svg aria-hidden="true" />,
 }));
 
-import { SearchLayout } from "./SearchLayout";
+import {
+  customerFacingRelationshipReason,
+  customerFacingRelationshipText,
+  SearchLayout,
+} from "./SearchLayout";
 import {
   clearRecordedProductEvents,
   getRecordedProductEvents,
@@ -185,6 +189,12 @@ describe("SearchLayout product events", () => {
     ));
     await waitForCondition(() => getRecordedProductEvents().some((event) => event.name === "context_search_result_action_created"));
 
+    expect(container.textContent).toContain("발신자 맥락");
+    expect(container.textContent).toContain("다음 행동");
+    expect(container.textContent).not.toContain("sender_context");
+    expect(container.textContent).not.toContain("thread-contract");
+    expect(container.textContent).not.toContain("<contract-source@example.com>");
+
     expect(getRecordedProductEvents().some((event) =>
       event.name === "context_search_result_action_created" &&
       event.payload.result_id === 202 &&
@@ -193,4 +203,68 @@ describe("SearchLayout product events", () => {
     )).toBe(true);
     expect(JSON.stringify(getRecordedProductEvents())).not.toContain("계약");
   });
+
+  it.each([
+    ["summarize_then_archive", "요약 후 보관합니다."],
+    ["track_reply_and_tasks", "답장과 후속 작업을 확인합니다."],
+    ["prepare_response_draft", "답장 초안을 준비합니다."],
+    ["classify_sender", "발신자 관계를 확인합니다."],
+  ])("maps production relationship action %s to customer copy", (nextAction, expectedCopy) => {
+    expect(customerFacingRelationshipText(nextAction, "후속 작업을 확인합니다.")).toBe(
+      expectedCopy,
+    );
+  });
+
+  it.each(["reply.follow-up", "reply/follow_up", "reply follow_up", "회신_대기", ""])(
+    "fails closed for non-catalog relationship action %s",
+    (nextAction) => {
+    expect(customerFacingRelationshipText(nextAction, "후속 작업을 확인합니다.")).toBe(
+      "후속 작업을 확인합니다.",
+    );
+    },
+  );
+
+  it.each([
+    ["summarize_then_archive", "핵심 내용을 확인한 뒤 정리할 수 있습니다."],
+    ["track_reply_and_tasks", "답장 여부와 이어서 할 일을 놓치지 않도록 제안했습니다."],
+    ["prepare_response_draft", "대화를 이어갈 답장이 필요한 관계입니다."],
+    ["classify_sender", "알맞은 후속 행동을 정하려면 발신자 관계 확인이 필요합니다."],
+    ["unknown_action", "선택한 원본과 발신자 관계를 바탕으로 제안했습니다."],
+  ])("maps relationship reason for %s to customer copy", (nextAction, expectedCopy) => {
+    expect(customerFacingRelationshipReason(nextAction)).toBe(expectedCopy);
+  });
+
+  it("shows customer-facing copy when relationship loading fails", async () => {
+    vi.stubGlobal("fetch", vi.fn((input: RequestInfo | URL) => {
+      const url = String(input);
+      if (url.endsWith("/api/search")) {
+        return Promise.resolve(jsonResponse({ results: [{
+          id: 1,
+          source_message_id: "source@example.com",
+          subject: "Search result",
+          sender: "pm@example.com",
+          date: "2026-05-20T09:00:00Z",
+          snippet: "Result",
+          thread_id: "thread-1",
+          reply_count: 0,
+          score: 0.9,
+        }] }));
+      }
+      if (url.includes("/api/ontology/relationships?")) {
+        return Promise.reject(new Error("relationship service unavailable"));
+      }
+      return Promise.reject(new Error(`Unexpected fetch: ${url}`));
+    }));
+
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+    await act(async () => {
+      root?.render(<SearchLayout />);
+    });
+    await waitForCondition(() =>
+      container?.textContent?.includes("발신자 관계를 불러오지 못했습니다.") ?? false,
+    );
+    expect(container.textContent).not.toContain("DAG");
+  });
 });
diff --git a/frontend/src/components/SearchLayout.tsx b/frontend/src/components/SearchLayout.tsx
index 92f16b184..5cf5ad72f 100644
--- a/frontend/src/components/SearchLayout.tsx
+++ b/frontend/src/components/SearchLayout.tsx
@@ -56,7 +56,45 @@ const EVIDENCE_KIND_LABELS: Record<string, string> = {
 
 function evidenceKindLabel(kind: string | null | undefined) {
   if (!kind || kind === "email_body") return null;
-  return EVIDENCE_KIND_LABELS[kind] ?? kind;
+  return EVIDENCE_KIND_LABELS[kind] ?? "연결 근거";
+}
+
+const RELATIONSHIP_TYPE_LABELS: Record<string, string> = {
+  sender_context: "발신자 맥락",
+  colleague: "업무 관계",
+};
+
+function relationshipTypeLabel(relationshipType: string) {
+  return RELATIONSHIP_TYPE_LABELS[relationshipType.trim().toLowerCase()] ?? "연결 관계";
+}
+
+const CUSTOMER_FACING_RELATIONSHIP_ACTIONS: Record<string, string> = {
+  summarize_then_archive: "요약 후 보관합니다.",
+  track_reply_and_tasks: "답장과 후속 작업을 확인합니다.",
+  prepare_response_draft: "답장 초안을 준비합니다.",
+  classify_sender: "발신자 관계를 확인합니다.",
+  "계약 검토 담당자를 확인합니다.": "계약 검토 담당자를 확인합니다.",
+  "후속 작업을 확인합니다.": "후속 작업을 확인합니다.",
+};
+
+const CUSTOMER_FACING_RELATIONSHIP_REASONS: Record<string, string> = {
+  summarize_then_archive: "핵심 내용을 확인한 뒤 정리할 수 있습니다.",
+  track_reply_and_tasks: "답장 여부와 이어서 할 일을 놓치지 않도록 제안했습니다.",
+  prepare_response_draft: "대화를 이어갈 답장이 필요한 관계입니다.",
+  classify_sender: "알맞은 후속 행동을 정하려면 발신자 관계 확인이 필요합니다.",
+};
+
+export function customerFacingRelationshipText(
+  relationshipAction: string,
+  fallbackCopy: string,
+) {
+  const normalizedAction = relationshipAction.trim();
+  return CUSTOMER_FACING_RELATIONSHIP_ACTIONS[normalizedAction] ?? fallbackCopy;
+}
+
+export function customerFacingRelationshipReason(relationshipAction: string) {
+  return CUSTOMER_FACING_RELATIONSHIP_REASONS[relationshipAction.trim()] ??
+    "선택한 원본과 발신자 관계를 바탕으로 제안했습니다.";
 }
 
 type SearchResponse = {
@@ -189,7 +227,7 @@ function SenderDagPanel({
         aria-live="polite"
         className="rounded-lg border border-border bg-background p-4 text-sm font-semibold text-muted-foreground"
       >
-        발신자 DAG를 불러오는 중입니다.
+        발신자 관계를 불러오는 중입니다.
       </div>
     );
   }
@@ -212,7 +250,7 @@ function SenderDagPanel({
         {canCapture ? (
           <div className="mt-3 flex flex-col gap-2 sm:flex-row sm:items-center sm:justify-between">
             <p className="text-xs">
-              원본 메일의 sender/thread 근거로 관계와 다음 액션을 캡처합니다.
+              선택한 원본 메일을 기준으로 관계와 다음 행동을 확인합니다.
             </p>
             <button
               type="button"
@@ -255,28 +293,27 @@ function SenderDagPanel({
               </p>
             </div>
             <div className="shrink-0 rounded-full bg-primary/10 px-3 py-1 text-xs font-bold text-primary">
-              {relationship.relationship_type} ·{" "}
+              {relationshipTypeLabel(relationship.relationship_type)} ·{" "}
               {(relationship.confidence_score * 100).toFixed(0)}%
             </div>
           </div>
           <div className="mt-4 grid gap-2 text-xs font-semibold text-muted-foreground sm:grid-cols-2">
             <div className="rounded border border-border bg-card px-3 py-2">
               <p className="break-all text-foreground">
-                {relationship.next_action}
+                {customerFacingRelationshipText(
+                  relationship.next_action,
+                  "후속 작업을 확인합니다.",
+                )}
               </p>
-              <p className="mt-1">Agent next action</p>
+              <p className="mt-1">다음 행동</p>
             </div>
             <div className="rounded border border-border bg-card px-3 py-2">
               <p className="break-words text-foreground">
-                {relationship.action_reason}
+                {customerFacingRelationshipReason(relationship.next_action)}
               </p>
               <p className="mt-1">판단 근거</p>
             </div>
           </div>
-          <p className="mt-3 break-words rounded bg-secondary/40 px-3 py-2 text-[11px] font-semibold text-muted-foreground">
-            source={relationship.source_message_id ?? "global"} / thread=
-            {relationship.source_thread_id ?? "none"}
-          </p>
         </article>
       ))}
     </div>
@@ -531,7 +568,7 @@ export function SearchLayout() {
         setRelationshipState({
           sourceKey: activeOntologySourceKey,
           items: [],
-          error: "발신자 DAG를 불러오지 못했습니다.",
+          error: "발신자 관계를 불러오지 못했습니다.",
         });
       });
 
@@ -893,10 +930,10 @@ export function SearchLayout() {
                           <div className="rounded-xl border border-border bg-card p-4">
                             <p className="text-xs font-black text-primary">증거 바인딩</p>
                             <p className="mt-2 font-semibold text-foreground">
-                              {activeResult.source_message_id ? "원본 메시지 필터로 관계 API를 조회합니다." : "원본 메시지 필터가 없는 결과입니다."}
+                              {activeResult.source_message_id ? "선택한 원본 메일을 기준으로 관계를 확인합니다." : "연결할 원본 메일이 없는 결과입니다."}
                             </p>
                             <p className="mt-2 text-xs leading-5 text-muted-foreground">
-                              관계 조회는 선택된 맥락 검색 결과의 source/thread 범위 안에서만 수행됩니다.
+                              다른 메일의 관계가 섞이지 않도록 선택한 결과 안에서만 확인합니다.
                             </p>
                           </div>
                           <div className="rounded-xl border border-border bg-card p-4">
@@ -939,7 +976,7 @@ export function SearchLayout() {
                 <div className="flex items-center justify-between gap-3">
                   <h2 className="text-lg font-bold">관계 맥락과 타임라인</h2>
                   <span className="rounded-full bg-primary/10 px-3 py-1 text-xs font-bold text-primary">
-                    source/thread API 연결
+                    원본 근거 연결
                   </span>
                 </div>
 
@@ -951,7 +988,7 @@ export function SearchLayout() {
                         aria-hidden="true"
                       />
                       <h3 className="text-lg font-bold">
-                        발신자 DAG (Ontology)
+                        발신자 관계
                       </h3>
                     </div>
                     <SenderDagPanel
@@ -977,7 +1014,7 @@ export function SearchLayout() {
                         className="size-5 text-primary"
                         aria-hidden="true"
                       />
-                      <h3 className="text-lg font-bold">타임라인 (Timeline)</h3>
+                      <h3 className="text-lg font-bold">활동 흐름</h3>
                     </div>
                     <div className="relative ml-3 space-y-6 border-l-2 border-border">
                       <div className="relative pl-6">
@@ -999,7 +1036,7 @@ export function SearchLayout() {
                         </h4>
                         <p className="mt-1 flex items-center gap-1 text-xs text-muted-foreground">
                           <CheckCircle2 className="size-3" aria-hidden="true" />
-                          thread reply_count={activeResult.reply_count ?? 1}
+                          답장 {activeResult.reply_count ?? 1}건
                         </p>
                       </div>
                       {activeResult.thread_id ? (
@@ -1013,7 +1050,7 @@ export function SearchLayout() {
                               className="size-4"
                               aria-hidden="true"
                             />
-                            {activeResult.thread_id}
+                            메일 흐름 연결됨
                           </h4>
                         </div>
                       ) : null}
diff --git a/frontend/tests/e2e/dashboard-branding.spec.ts b/frontend/tests/e2e/dashboard-branding.spec.ts
index f89f5149e..a9890163f 100644
--- a/frontend/tests/e2e/dashboard-branding.spec.ts
+++ b/frontend/tests/e2e/dashboard-branding.spec.ts
@@ -1376,14 +1376,17 @@ test('renders API-backed context search sender DAG and reply tracking', async ({
     expect(ontologyHeaders[headerName]).toBeUndefined();
   }
 
-  await expect(page.getByRole('heading', { name: '맥락 검색' })).toBeAttached();
+  await expect(page.getByRole('heading', { name: '맥락 검색', exact: true })).toBeAttached();
   await expect(page.getByRole('heading', { name: 'Q2 출시 계획 및 우선순위 조정' }).first()).toBeVisible();
-  await expect(page.getByText('thread-q2').first()).toBeVisible();
+  await expect(page.getByText('메일 흐름 연결됨').first()).toBeVisible();
   await expect(page.getByText('답장 2건').first()).toBeVisible();
   await expect(page.getByText('관계 맥락과 타임라인')).toBeVisible();
-  await expect(page.getByText('발신자 DAG (Ontology)')).toBeVisible();
-  await expect(page.getByText('track_reply_and_tasks')).toBeVisible();
-  await expect(page.getByText('source=<q2@example.com> / thread=thread-q2')).toBeVisible();
+  await expect(page.getByText('발신자 관계')).toBeVisible();
+  await expect(page.getByText('답장과 후속 작업을 확인합니다.')).toBeVisible();
+  await expect(page.getByText('답장 여부와 이어서 할 일을 놓치지 않도록 제안했습니다.')).toBeVisible();
+  await expect(page.getByText('Same-domain sender; preserve reply and task follow-up.')).toHaveCount(0);
+  await expect(page.getByText('track_reply_and_tasks')).toHaveCount(0);
+  await expect(page.getByText('source=<q2@example.com> / thread=thread-q2')).toHaveCount(0);
   await expect(page.getByText('김지현 PM').first()).toBeVisible();
   const desktopOverflow = await page.evaluate(() => document.documentElement.scrollWidth - document.documentElement.clientWidth);
   expect(desktopOverflow).toBeLessThanOrEqual(1);
@@ -1392,7 +1395,7 @@ test('renders API-backed context search sender DAG and reply tracking', async ({
   await page.setViewportSize({ width: 390, height: 844 });
   await page.goto('/search');
   await expect(page.getByRole('heading', { name: 'Q2 출시 계획 및 우선순위 조정' }).first()).toBeVisible();
-  await expect(page.getByText('thread-q2').first()).toBeVisible();
+  await expect(page.getByText('메일 흐름 연결됨').first()).toBeVisible();
   const mobileOverflow = await page.evaluate(() => document.documentElement.scrollWidth - document.documentElement.clientWidth);
   expect(mobileOverflow).toBeLessThanOrEqual(1);
   await page.screenshot({ path: testInfo.outputPath('search-dag-reply-mobile.png'), fullPage: false });
@@ -1419,9 +1422,9 @@ test('renders API-backed context search sender DAG and reply tracking', async ({
   });
   expect(detailScrollMetrics.maxScroll).toBeGreaterThan(0);
   expect(detailScrollMetrics.after).toBeGreaterThan(detailScrollMetrics.before);
-  await page.getByText('발신자 DAG (Ontology)').scrollIntoViewIfNeeded();
-  await expect(page.getByText('track_reply_and_tasks')).toBeVisible();
-  await page.getByText('track_reply_and_tasks').scrollIntoViewIfNeeded();
+  await page.getByText('발신자 관계').scrollIntoViewIfNeeded();
+  await expect(page.getByText('답장과 후속 작업을 확인합니다.')).toBeVisible();
+  await page.getByText('답장과 후속 작업을 확인합니다.').scrollIntoViewIfNeeded();
   await page.screenshot({ path: testInfo.outputPath('search-dag-reply-mobile-dag.png'), fullPage: false });
   await page.getByText('관계 이해').scrollIntoViewIfNeeded();
   await expect(page.getByText('관계 이해')).toBeVisible();